1 // Copyright 2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
12 use ast::{MetaItem, Item, Expr};
14 use ext::base::ExtCtxt;
15 use ext::build::AstBuilder;
16 use ext::deriving::generic::*;
17 use ext::deriving::generic::ty::*;
18 use parse::token::InternedString;
21 pub fn expand_deriving_totalord<F>(cx: &mut ExtCtxt,
28 let inline = cx.meta_word(span, InternedString::new("inline"));
29 let attrs = vec!(cx.attribute(span, inline));
30 let trait_def = TraitDef {
32 attributes: Vec::new(),
33 path: Path::new(vec!("std", "cmp", "Ord")),
34 additional_bounds: Vec::new(),
35 generics: LifetimeBounds::empty(),
39 generics: LifetimeBounds::empty(),
40 explicit_self: borrowed_explicit_self(),
41 args: vec!(borrowed_self()),
42 ret_ty: Literal(Path::new(vec!("std", "cmp", "Ordering"))),
44 combine_substructure: combine_substructure(box |a, b, c| {
49 associated_types: Vec::new(),
52 trait_def.expand(cx, mitem, item, push)
56 pub fn ordering_collapsed(cx: &mut ExtCtxt,
58 self_arg_tags: &[ast::Ident]) -> P<ast::Expr> {
59 let lft = cx.expr_ident(span, self_arg_tags[0]);
60 let rgt = cx.expr_addr_of(span, cx.expr_ident(span, self_arg_tags[1]));
61 cx.expr_method_call(span, lft, cx.ident_of("cmp"), vec![rgt])
64 pub fn cs_cmp(cx: &mut ExtCtxt, span: Span,
65 substr: &Substructure) -> P<Expr> {
66 let test_id = cx.ident_of("__test");
67 let equals_path = cx.path_global(span,
68 vec!(cx.ident_of("std"),
70 cx.ident_of("Ordering"),
71 cx.ident_of("Equal")));
83 let __test = ::std::cmp::Ord::cmp(&self_field1, &other_field1);
84 if other == ::std::cmp::Ordering::Equal {
85 let __test = ::std::cmp::Ord::cmp(&self_field2, &other_field2);
86 if __test == ::std::cmp::Ordering::Equal {
95 FIXME #6449: These `if`s could/should be `match`es.
98 // foldr nests the if-elses correctly, leaving the first field
99 // as the outermost one, and the last as the innermost.
101 |cx, span, old, self_f, other_fs| {
103 // if __test == ::std::cmp::Ordering::Equal {
110 let other_f = match other_fs {
112 _ => cx.span_bug(span, "not exactly 2 arguments in `derive(PartialOrd)`"),
116 cx.expr_addr_of(span, self_f),
117 cx.expr_addr_of(span, other_f.clone()),
120 cx.expr_call_global(span, cmp_path.clone(), args)
123 let assign = cx.stmt_let(span, false, test_id, new);
125 let cond = cx.expr_binary(span, ast::BiEq,
126 cx.expr_ident(span, test_id),
127 cx.expr_path(equals_path.clone()));
128 let if_ = cx.expr_if(span,
130 old, Some(cx.expr_ident(span, test_id)));
131 cx.expr_block(cx.block(span, vec!(assign), Some(if_)))
133 cx.expr_path(equals_path.clone()),
134 box |cx, span, (self_args, tag_tuple), _non_self_args| {
135 if self_args.len() != 2 {
136 cx.span_bug(span, "not exactly 2 arguments in `derives(Ord)`")
138 ordering_collapsed(cx, span, tag_tuple)